Turbine-controlling mechanism.



J. B. WILSON..

TURBINE CONTROLLING MECHANISM.

APPLICATION FILED JUNE 22, I912.

Patented Au 28, 1917.

2 SHEETSSHEET 1.

/N VE N TOR HI ATTORNEY IN FACT.

J. B. WILSON.

TURBINE CONTROLLING MECHANISM.

APPLICATION FILED JUNE 22, 1912.

1,238,374. Patented Aug. 28, 1917.

2 SHEETS-SHEET 2- r INVENTOR. N E F a X J M @Q By K ATTORNEY IN FACT.

I UNITED STATES PATENT ormcn JOSEPH B. WILSON, CHICAGO, ILLINOIS, ASSIGNOB TO THE WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

TURBINE-CONTROLLING MECHANISM.

Specification of Letters Patent. Patented Aug. 28, 1917'.

Application filed June 22, 1912. Serial No. 705,273.

To all whom it may concern:

Bev it known that I, JOSEPH B. WILSON, a

vention in Turbine-Controlling Mechanism, of which the following is a specification.

This invention relates to turbine-controlling mechanism.

One of the objects is to maintain a constant speed at a given load irrespective of pressure of the steam supplied to the system.

As generally practised, turbines have heretofore been provided with governors which control a valve or valves through a relay or relays so that the positions of the valves 'will determine the amount of steam fed into the turbine. This construction has generally been suflicient to take care of regu lation when the fluid pressure supplied is practically constant, but it has not proved to be satisfactory where the fluid supplied varies in pressure. In practice it has especially been-proved unsatisfactory in connec. tion with mixed pressure turbines; that is, a turbine operating on exhaust steam the supply of which is adapted to-be augmented by steam at higher pressure should the exhaust steam become depleted or fail.

According to my invention, the turbine may be connected to the exhaust of a high pressure engine, and in addition to this, have connection with a source of high pressure, steam, as for example, a boiler. In such an event a constant speed would be maintained at a given load whether there happened to be more than enough or just enough exhaust steam availableto carry the load; for example, at half load if the pressure in the line were ten pounds and more exhaust steam were available than was necessary to carry the load, the excess steam would be permitted to escape to atmosphere, or be carriedoif or shunted around the turb-ine.. If the pressure in the main should drop, due to a decrease in the exhaust steam supply, the valve would open wider to accommodate the steam at the decreased pressure without necessitating a change in the speed.

This invention is also applicable to a high pressure condensing turbine driving a constant load. I I

In the drawings: F'gure 1 is a diagrammaticview of a turbine receiving motive fluid supply in accordance with my invention; and

Fig. 2 is a similar view of a slightly modified form.

Referring now to the drawings by numerals of reference, 1 designates a turbine here shown as a low pressure turbine and which is adapted to drive a constant load, as for example, a generator 2. The. turbine 1 is here shown as being provided with a supply pipe 3 receiving the exhaust from a high pressure unit illustrated as a reciprocating engine 4. The pipe 3 is provided with a blow-01f valve 5 and between the ends of, pipe 3 is a valve casing 6 in which there is a balanced piston valve 7 adapted to be seated upon the seats 8 and 9 of the valve casing 6. A valve stem 10 is connected to the valve 7 and carries a collar 11 against which one end of a spring 12 bears, this spring being about equal to the normal pressure of the steam entering the turbine. The other end of the spring rests upon a seat 13 on'the valve casing 6. Connected by a bracket to the valve casing 6 is shown a high pressure valve casing 14 receiving steam from high pressure, as for example, a boiler through the pipe 15 and discharging it through a pipe 16 into the pipe 3. Within the valve casing 14 is a balanced valve of the usual construction having a stem 17 with a slotted extension 18 thereon in which is provided a .26 adapted to admit fluid into the cylinder on opposite sides of the piston 24 and exhaust it therefrom in accordance with the position of the valves on the relay stem 27 which admit fluid to said cylinder: The relay stem 27 is provided with valves 28 and 29 which are adapted to cover and uncover the ports 28 and 29 respectively with collars 30 and 31 acting as abutments orfstops to prevent leakage of oil. The pipes 32 and 33 connected to the relay cylinder 35: are exhaust pipes, while the pipe designated by the reference numeral 35 is a supply pipe to admit oil into the relay and through it into the cylinder 25. The relay stem 27 isvillustratedas being connected to a floating lever 36, one end of which is connected to a governor or speed responsive device, the other end of the floating lever 36 being connected to the stem 38 of the piston 39 in the cylinder 40. The stem 38 is provided with a seat 41 against which bears a spring 42 one end of which rests against a seat 43 in the bracket 44 so that the normal tendency of the spring 42 is to seat or exert a downward pressure upon the piston 39. Leading from v with the conduit 3 in advance of the inlet to the turbine and also communicates with the cylinder on one side of the piston-39, and the pipe .47 communicates with the exhaust end of the turbine 1 and with'the cylinder 40 on the opposite side of the piston 39, the piston 39 will be affected by differences of pressure existing in thepipes 45 and 47; for example, if the normal pressure in the pipe 3 were 14% pounds and the vacuum at the exhaust end of the turbine happened to be 1 pound absolute, there would be a definite position for the piston 39. If the pressure in the pipe 3 should drop "below 14% pounds or increase above it, the piston 39 would be affected. If the vacuum at the exhaust end of the turbine were reduced, there would be an increase of pressure in the pipe 47, and although the pressure in the pipe 3 remained constant, thepiston 39 would be affected because there would be a difierence of pressures on opposite sides of the piston 39. It will, therefore, be apparent that any change in the pressure in the pipe 3 will be felt by the piston 39 irrespective of the pressure in the pipe 47, and any variation in pressure in the pipe 47 will be felt by the piston 39 irrespective of the pressure in the pipe 3.

Now, suppose the turbine 1 is operating at its full load and that there is enough exhaust steam from the reciprocating engine to maintain the proper speed; in the event that thepressure in the pipe 3 falls the piston 39 Will descend because the drop in pressure in pipe-45 will cause a drop 1n pressure on one side of the piston 39 and the descending of the piston 39 will operate. the oil relay stem 27 to open the port 29 and admit fluid through the port 26' to the under side of the piston 24 which in raising will cause the valve 7 to open more to accommodate the steam at the reduced pressure so as to maintain the speedof the turbine 1. If the continued upward movement of the valve 7 fails to supply suflicient exhaust steamto turbine.

maintain the desired speed on the turbine 1, a movement of lever 20 beyond the full open movement of the valve 7 will unseat the high pressure valve in the casing 14 and admit enough steam at boiler pressure to augment thesupply of low pressure steam sufiicient to maintain the required speed. If, now, an additional amount of low pressure steam is available; that is, suppose there is an abundance of low pressure steam being supplied from the reciprocating engine, or too much high pressure steam, the pressure will increase; the piston 39 will be raised; the oil relay will admit oil or similar fluid to the top of the piston 24 and exhaust it from the bottom of the cylinder 25 so that pipe 3 tomaintain thedesired speed of the It is to be understood that the block 19 has a lost motion or sliding movement in the slotted projection 18 so that the valve in the casing 14 does not begin to unseat until the valve 7 has moved to its fullestopen extent. The function of the blowoff valve 5 will-be obvious, it being generally understood that devices of this kind are placed in lines for the purpose of relieving excess pressure in the pipe to which they are attached, so in this case any excess pressure in the pipe 3 will berelieved through the blow-off valve 5.

It is to be understood that the governor or speed responsive device 37 operates in the usual way performing its usual functions, my invention consisting in making the pressure drop through the unit vary with the governor movement and having a commechanism that a certain speed will be main-.

tained for a certain load irrespective of variations in the fluid supplied from the low pressure source for if the fluid supplied from that source is insuflicient, fluid from an additional source may be admitted.

In Fig. 2 I have shown a slightly modified form of a turbine-controlling system in which the turbine 1 issupplied from a pipe 3 receiving exhaust steam from a reciprocating engine 4. Between the ends of the pipe 3 is a valve casing 6 having a balanced valve 7- therein and adapted to be seatedon seats 8 and 9. Leading from the valve 7 is a stem 10 on one end of which is a piston 50 in a cylinder 51. Abovethe cylinder 51 is shown a cylinder 52 having a piston 53 therein, the stem 54 of which is provided with a seat 55 against which one end ofa spring 56 bears, the other end of said spring bearing against a yoke 57 The piston stem 54 is connected to one end of a floating lever 58, the other end of which is connected to,

a link 59 on the governor 37. Between the endsof the lever 58'is an oil relay stem 27 corresponding to the oil relay described in connection with Fig. 1, which admits fluid to the opposite sides of the piston through the ports 60 and 61. The pipe 62 leads from the valve casing 6 to the cylinder 52 on the under side of the piston 53, while'a pipe 63 leads from the cylinder 52 on the opposite sides of the piston 53 to the turbine 1. 5 is the blow-ofl valve in the pipe 3. The pipe 64 connected to the pipe 3 is provided with a valve casing 65 in which is a balanced valve 67 similar to that designated by the reference numeral 7 and is connected by a flexible connection 68 to the valve 7'. The pipe 64 may be connected to another engine similar to the one designated 4, 'or may be connected-to boiler or auxiliaries if desired, the said pipe 64 simply leading from another source of supply.

The operation of the mechanism illustrated in Fig. 2 is'similar to that described in Fig. 1, the governor 37 acting in its usual way, but should the supply in the pipe 3 fall, the piston 53 would move downward,

operating the oil relay so as to push the piston 50 upward, opening the valve 7'. If, on the other hand, the supply became excessive, the piston 53 would be-moved up; the oilrelay would admit fluid tothe upper side of the piston 50 and impart a closing movement to the valve 7 In the foregoing description it will be obvious that the regulation of the turbine will be such thata constant speed will be maintained for a constant load irrespective ofthe pressure within the pipe 3 and that the compensating device assisting the governor will position the valves in respect to the governor in accordance with the pressure maintained.

' Having thus described -my invention, what I claim is:

1. The combination with aturbine, a supply pipe, avalve in the supply pipe, and a speed responsive device controlling said valve, of a single piston responsive to variations in pressure in the supply pipe and at the exhaust end of the turbine for changing thepositi'on of the valve independent of the speed responsive device.

2. A turbine, a conduit leading steam into said turbine, a valve in said conduit, a governor for controlling said valve, a piston for controlling said valve, a cylinder surrounding said piston, a pipe leading from the cylinder to the conduit, a pipe leading from the cylinderto the turbine, and an oil relay responsive to thepiston and for operating said valve.

fluid from said source to the turbine, a

valve motor responsive in operation to variations in the pressure at the exhaust of the turbine for actuating said valve, and an auxiliary valve for at times delivering high pressure motive fluid to' the first mentioned valve.

4. A turbme controlmechanism, comprising a source of fluid pressurefor the turbine, a valve for controlling the delivery of fluid from said source to theturbine, a valve motor responsive in operation to variations in the pressure at the exhaust of the turbine for actuating said valve, an auxiliary valve for at times admitting an additional supply of motive fluid to the first mentioned valve,

and a speedresponsive governor SE01" controlling the operatioh of thevalve motor.

5. In combination with a turbine, a con-* trol mechanism comprlsmg a source of low preswure motive fluid, a governor, a valve controlled by said governor for delivering fluid to the turbine, a source of high pres sure motive fluid, a valve for controlling the delivery of fluid from said high pressure source to said first mentioned valve, and

means responsive to variations in the presfirst mentioned valve independently of the governor. v

6. In combination with a turbine, a control mechanism comprising a source of low pressure motive fluid, a source ofhigh pressure motive fluid, a high pressure valve for said valves, and means responsive to variations in pressure of the fluid delivered to the low pressure valve for controlling the operation of the low pressure valve independently of the governor.

7. In combination with a turbine, a control mechanism comprising a source of low pressure motive fluid, a source of high pressure motive fluid, a high pressure valve for delivering fluid from said high pressure source to augment the low pressure fluid supply, a low pressure valve for controlling the delivery of fluid from said low pressure source and of the. fluid from the high pressure valve to said turbine, a governor responsive to speed variations of the turbine for controlling the operation of each ofv said valves, and means responsive to pressure variations'of the 'fluid delivered to the low pressure valve for controlling the operation of both of said valves independently of the governor.

8. In combination with a turbine having a fluid inlet port, a control mechanism comprising a passage communicating with said port and for delivering fluid to the turbine from a source of low pressure supply, a passage communicating with an auxiliary source of supply and with said port for delivering an auxiliary supply of motive fluid to the turbine, a separate valve for controlling the delivery of motive fluid through each of said passages, a governor responsive to variations in speed of the turbine 'for controlling the operation of said valves and means responsive to variations "in the pressure of fluid from said source of low pressure supply for controlling the operation of both of said valves independently of" the speed of the turbine.

9; In combination with a turbine, a high pressure source of fluid supply, a low pressure source of fluid supply, valves for controlling the delivering of fluid to the turbine from both of said sources, a speed responsive device driven by the turbine, a motor responsive to the operation ofsaid speed responsive device for controlling the operation of said valves to vary the amount of fluid delivered to the turbine in response to variations in the speed thereof, and means responsive to the differential pressure between the low pressure source of supply and theturbine exhaust for moving both valves toward a closing position independently of the'operation of the speed responsive device, in response to an increase in the differential pressure.

In testimony whereof, I have hereunto subscribed-my name this day of June,

JOSEPH B. WILSON. Witnesses:

ARCHIBALD W. IIELLIS, GEO. E. HEDIGER. 

